1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2019 Laurent Pinchart <laurent.pinchart@ideasonboard.com> 4 */ 5 6 #include <linux/gpio/consumer.h> 7 #include <linux/i2c.h> 8 #include <linux/interrupt.h> 9 #include <linux/media-bus-format.h> 10 #include <linux/module.h> 11 #include <linux/mutex.h> 12 #include <linux/of.h> 13 #include <linux/of_device.h> 14 #include <linux/platform_device.h> 15 #include <linux/regulator/consumer.h> 16 17 #include <drm/drm_atomic_helper.h> 18 #include <drm/drm_bridge.h> 19 #include <drm/drm_edid.h> 20 21 struct display_connector { 22 struct drm_bridge bridge; 23 24 struct gpio_desc *hpd_gpio; 25 int hpd_irq; 26 27 struct regulator *dp_pwr; 28 struct gpio_desc *ddc_en; 29 }; 30 31 static inline struct display_connector * 32 to_display_connector(struct drm_bridge *bridge) 33 { 34 return container_of(bridge, struct display_connector, bridge); 35 } 36 37 static int display_connector_attach(struct drm_bridge *bridge, 38 enum drm_bridge_attach_flags flags) 39 { 40 return flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR ? 0 : -EINVAL; 41 } 42 43 static enum drm_connector_status 44 display_connector_detect(struct drm_bridge *bridge) 45 { 46 struct display_connector *conn = to_display_connector(bridge); 47 48 if (conn->hpd_gpio) { 49 if (gpiod_get_value_cansleep(conn->hpd_gpio)) 50 return connector_status_connected; 51 else 52 return connector_status_disconnected; 53 } 54 55 if (conn->bridge.ddc && drm_probe_ddc(conn->bridge.ddc)) 56 return connector_status_connected; 57 58 switch (conn->bridge.type) { 59 case DRM_MODE_CONNECTOR_DVIA: 60 case DRM_MODE_CONNECTOR_DVID: 61 case DRM_MODE_CONNECTOR_DVII: 62 case DRM_MODE_CONNECTOR_HDMIA: 63 case DRM_MODE_CONNECTOR_HDMIB: 64 /* 65 * For DVI and HDMI connectors a DDC probe failure indicates 66 * that no cable is connected. 67 */ 68 return connector_status_disconnected; 69 70 case DRM_MODE_CONNECTOR_Composite: 71 case DRM_MODE_CONNECTOR_SVIDEO: 72 case DRM_MODE_CONNECTOR_VGA: 73 default: 74 /* 75 * Composite and S-Video connectors have no other detection 76 * mean than the HPD GPIO. For VGA connectors, even if we have 77 * an I2C bus, we can't assume that the cable is disconnected 78 * if drm_probe_ddc fails, as some cables don't wire the DDC 79 * pins. 80 */ 81 return connector_status_unknown; 82 } 83 } 84 85 static struct edid *display_connector_get_edid(struct drm_bridge *bridge, 86 struct drm_connector *connector) 87 { 88 struct display_connector *conn = to_display_connector(bridge); 89 90 return drm_get_edid(connector, conn->bridge.ddc); 91 } 92 93 /* 94 * Since this bridge is tied to the connector, it acts like a passthrough, 95 * so concerning the output bus formats, either pass the bus formats from the 96 * previous bridge or return fallback data like done in the bridge function: 97 * drm_atomic_bridge_chain_select_bus_fmts(). 98 * This supports negotiation if the bridge chain has all bits in place. 99 */ 100 static u32 *display_connector_get_output_bus_fmts(struct drm_bridge *bridge, 101 struct drm_bridge_state *bridge_state, 102 struct drm_crtc_state *crtc_state, 103 struct drm_connector_state *conn_state, 104 unsigned int *num_output_fmts) 105 { 106 struct drm_bridge *prev_bridge = drm_bridge_get_prev_bridge(bridge); 107 struct drm_bridge_state *prev_bridge_state; 108 109 if (!prev_bridge || !prev_bridge->funcs->atomic_get_output_bus_fmts) { 110 struct drm_connector *conn = conn_state->connector; 111 u32 *out_bus_fmts; 112 113 *num_output_fmts = 1; 114 out_bus_fmts = kmalloc(sizeof(*out_bus_fmts), GFP_KERNEL); 115 if (!out_bus_fmts) 116 return NULL; 117 118 if (conn->display_info.num_bus_formats && 119 conn->display_info.bus_formats) 120 out_bus_fmts[0] = conn->display_info.bus_formats[0]; 121 else 122 out_bus_fmts[0] = MEDIA_BUS_FMT_FIXED; 123 124 return out_bus_fmts; 125 } 126 127 prev_bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state, 128 prev_bridge); 129 130 return prev_bridge->funcs->atomic_get_output_bus_fmts(prev_bridge, prev_bridge_state, 131 crtc_state, conn_state, 132 num_output_fmts); 133 } 134 135 /* 136 * Since this bridge is tied to the connector, it acts like a passthrough, 137 * so concerning the input bus formats, either pass the bus formats from the 138 * previous bridge or MEDIA_BUS_FMT_FIXED (like select_bus_fmt_recursive()) 139 * when atomic_get_input_bus_fmts is not supported. 140 * This supports negotiation if the bridge chain has all bits in place. 141 */ 142 static u32 *display_connector_get_input_bus_fmts(struct drm_bridge *bridge, 143 struct drm_bridge_state *bridge_state, 144 struct drm_crtc_state *crtc_state, 145 struct drm_connector_state *conn_state, 146 u32 output_fmt, 147 unsigned int *num_input_fmts) 148 { 149 struct drm_bridge *prev_bridge = drm_bridge_get_prev_bridge(bridge); 150 struct drm_bridge_state *prev_bridge_state; 151 152 if (!prev_bridge || !prev_bridge->funcs->atomic_get_input_bus_fmts) { 153 u32 *in_bus_fmts; 154 155 *num_input_fmts = 1; 156 in_bus_fmts = kmalloc(sizeof(*in_bus_fmts), GFP_KERNEL); 157 if (!in_bus_fmts) 158 return NULL; 159 160 in_bus_fmts[0] = MEDIA_BUS_FMT_FIXED; 161 162 return in_bus_fmts; 163 } 164 165 prev_bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state, 166 prev_bridge); 167 168 return prev_bridge->funcs->atomic_get_input_bus_fmts(prev_bridge, prev_bridge_state, 169 crtc_state, conn_state, output_fmt, 170 num_input_fmts); 171 } 172 173 static const struct drm_bridge_funcs display_connector_bridge_funcs = { 174 .attach = display_connector_attach, 175 .detect = display_connector_detect, 176 .get_edid = display_connector_get_edid, 177 .atomic_get_output_bus_fmts = display_connector_get_output_bus_fmts, 178 .atomic_get_input_bus_fmts = display_connector_get_input_bus_fmts, 179 .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state, 180 .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state, 181 .atomic_reset = drm_atomic_helper_bridge_reset, 182 }; 183 184 static irqreturn_t display_connector_hpd_irq(int irq, void *arg) 185 { 186 struct display_connector *conn = arg; 187 struct drm_bridge *bridge = &conn->bridge; 188 189 drm_bridge_hpd_notify(bridge, display_connector_detect(bridge)); 190 191 return IRQ_HANDLED; 192 } 193 194 static int display_connector_probe(struct platform_device *pdev) 195 { 196 struct display_connector *conn; 197 unsigned int type; 198 const char *label = NULL; 199 int ret; 200 201 conn = devm_kzalloc(&pdev->dev, sizeof(*conn), GFP_KERNEL); 202 if (!conn) 203 return -ENOMEM; 204 205 platform_set_drvdata(pdev, conn); 206 207 type = (uintptr_t)of_device_get_match_data(&pdev->dev); 208 209 /* Get the exact connector type. */ 210 switch (type) { 211 case DRM_MODE_CONNECTOR_DVII: { 212 bool analog, digital; 213 214 analog = of_property_read_bool(pdev->dev.of_node, "analog"); 215 digital = of_property_read_bool(pdev->dev.of_node, "digital"); 216 if (analog && !digital) { 217 conn->bridge.type = DRM_MODE_CONNECTOR_DVIA; 218 } else if (!analog && digital) { 219 conn->bridge.type = DRM_MODE_CONNECTOR_DVID; 220 } else if (analog && digital) { 221 conn->bridge.type = DRM_MODE_CONNECTOR_DVII; 222 } else { 223 dev_err(&pdev->dev, "DVI connector with no type\n"); 224 return -EINVAL; 225 } 226 break; 227 } 228 229 case DRM_MODE_CONNECTOR_HDMIA: { 230 const char *hdmi_type; 231 232 ret = of_property_read_string(pdev->dev.of_node, "type", 233 &hdmi_type); 234 if (ret < 0) { 235 dev_err(&pdev->dev, "HDMI connector with no type\n"); 236 return -EINVAL; 237 } 238 239 if (!strcmp(hdmi_type, "a") || !strcmp(hdmi_type, "c") || 240 !strcmp(hdmi_type, "d") || !strcmp(hdmi_type, "e")) { 241 conn->bridge.type = DRM_MODE_CONNECTOR_HDMIA; 242 } else if (!strcmp(hdmi_type, "b")) { 243 conn->bridge.type = DRM_MODE_CONNECTOR_HDMIB; 244 } else { 245 dev_err(&pdev->dev, 246 "Unsupported HDMI connector type '%s'\n", 247 hdmi_type); 248 return -EINVAL; 249 } 250 251 break; 252 } 253 254 default: 255 conn->bridge.type = type; 256 break; 257 } 258 259 /* All the supported connector types support interlaced modes. */ 260 conn->bridge.interlace_allowed = true; 261 262 /* Get the optional connector label. */ 263 of_property_read_string(pdev->dev.of_node, "label", &label); 264 265 /* 266 * Get the HPD GPIO for DVI, HDMI and DP connectors. If the GPIO can provide 267 * edge interrupts, register an interrupt handler. 268 */ 269 if (type == DRM_MODE_CONNECTOR_DVII || 270 type == DRM_MODE_CONNECTOR_HDMIA || 271 type == DRM_MODE_CONNECTOR_DisplayPort) { 272 conn->hpd_gpio = devm_gpiod_get_optional(&pdev->dev, "hpd", 273 GPIOD_IN); 274 if (IS_ERR(conn->hpd_gpio)) { 275 if (PTR_ERR(conn->hpd_gpio) != -EPROBE_DEFER) 276 dev_err(&pdev->dev, 277 "Unable to retrieve HPD GPIO\n"); 278 return PTR_ERR(conn->hpd_gpio); 279 } 280 281 conn->hpd_irq = gpiod_to_irq(conn->hpd_gpio); 282 } else { 283 conn->hpd_irq = -EINVAL; 284 } 285 286 if (conn->hpd_irq >= 0) { 287 ret = devm_request_threaded_irq(&pdev->dev, conn->hpd_irq, 288 NULL, display_connector_hpd_irq, 289 IRQF_TRIGGER_RISING | 290 IRQF_TRIGGER_FALLING | 291 IRQF_ONESHOT, 292 "HPD", conn); 293 if (ret) { 294 dev_info(&pdev->dev, 295 "Failed to request HPD edge interrupt, falling back to polling\n"); 296 conn->hpd_irq = -EINVAL; 297 } 298 } 299 300 /* Retrieve the DDC I2C adapter for DVI, HDMI and VGA connectors. */ 301 if (type == DRM_MODE_CONNECTOR_DVII || 302 type == DRM_MODE_CONNECTOR_HDMIA || 303 type == DRM_MODE_CONNECTOR_VGA) { 304 struct device_node *phandle; 305 306 phandle = of_parse_phandle(pdev->dev.of_node, "ddc-i2c-bus", 0); 307 if (phandle) { 308 conn->bridge.ddc = of_get_i2c_adapter_by_node(phandle); 309 of_node_put(phandle); 310 if (!conn->bridge.ddc) 311 return -EPROBE_DEFER; 312 } else { 313 dev_dbg(&pdev->dev, 314 "No I2C bus specified, disabling EDID readout\n"); 315 } 316 } 317 318 /* Get the DP PWR for DP connector. */ 319 if (type == DRM_MODE_CONNECTOR_DisplayPort) { 320 int ret; 321 322 conn->dp_pwr = devm_regulator_get_optional(&pdev->dev, "dp-pwr"); 323 324 if (IS_ERR(conn->dp_pwr)) { 325 ret = PTR_ERR(conn->dp_pwr); 326 327 switch (ret) { 328 case -ENODEV: 329 conn->dp_pwr = NULL; 330 break; 331 332 case -EPROBE_DEFER: 333 return -EPROBE_DEFER; 334 335 default: 336 dev_err(&pdev->dev, "failed to get DP PWR regulator: %d\n", ret); 337 return ret; 338 } 339 } 340 341 if (conn->dp_pwr) { 342 ret = regulator_enable(conn->dp_pwr); 343 if (ret) { 344 dev_err(&pdev->dev, "failed to enable DP PWR regulator: %d\n", ret); 345 return ret; 346 } 347 } 348 } 349 350 /* enable DDC */ 351 if (type == DRM_MODE_CONNECTOR_HDMIA) { 352 conn->ddc_en = devm_gpiod_get_optional(&pdev->dev, "ddc-en", 353 GPIOD_OUT_HIGH); 354 355 if (IS_ERR(conn->ddc_en)) { 356 dev_err(&pdev->dev, "Couldn't get ddc-en gpio\n"); 357 return PTR_ERR(conn->ddc_en); 358 } 359 } 360 361 conn->bridge.funcs = &display_connector_bridge_funcs; 362 conn->bridge.of_node = pdev->dev.of_node; 363 364 if (conn->bridge.ddc) 365 conn->bridge.ops |= DRM_BRIDGE_OP_EDID 366 | DRM_BRIDGE_OP_DETECT; 367 if (conn->hpd_gpio) 368 conn->bridge.ops |= DRM_BRIDGE_OP_DETECT; 369 if (conn->hpd_irq >= 0) 370 conn->bridge.ops |= DRM_BRIDGE_OP_HPD; 371 372 dev_dbg(&pdev->dev, 373 "Found %s display connector '%s' %s DDC bus and %s HPD GPIO (ops 0x%x)\n", 374 drm_get_connector_type_name(conn->bridge.type), 375 label ? label : "<unlabelled>", 376 conn->bridge.ddc ? "with" : "without", 377 conn->hpd_gpio ? "with" : "without", 378 conn->bridge.ops); 379 380 drm_bridge_add(&conn->bridge); 381 382 return 0; 383 } 384 385 static int display_connector_remove(struct platform_device *pdev) 386 { 387 struct display_connector *conn = platform_get_drvdata(pdev); 388 389 if (conn->ddc_en) 390 gpiod_set_value(conn->ddc_en, 0); 391 392 if (conn->dp_pwr) 393 regulator_disable(conn->dp_pwr); 394 395 drm_bridge_remove(&conn->bridge); 396 397 if (!IS_ERR(conn->bridge.ddc)) 398 i2c_put_adapter(conn->bridge.ddc); 399 400 return 0; 401 } 402 403 static const struct of_device_id display_connector_match[] = { 404 { 405 .compatible = "composite-video-connector", 406 .data = (void *)DRM_MODE_CONNECTOR_Composite, 407 }, { 408 .compatible = "dvi-connector", 409 .data = (void *)DRM_MODE_CONNECTOR_DVII, 410 }, { 411 .compatible = "hdmi-connector", 412 .data = (void *)DRM_MODE_CONNECTOR_HDMIA, 413 }, { 414 .compatible = "svideo-connector", 415 .data = (void *)DRM_MODE_CONNECTOR_SVIDEO, 416 }, { 417 .compatible = "vga-connector", 418 .data = (void *)DRM_MODE_CONNECTOR_VGA, 419 }, { 420 .compatible = "dp-connector", 421 .data = (void *)DRM_MODE_CONNECTOR_DisplayPort, 422 }, 423 {}, 424 }; 425 MODULE_DEVICE_TABLE(of, display_connector_match); 426 427 static struct platform_driver display_connector_driver = { 428 .probe = display_connector_probe, 429 .remove = display_connector_remove, 430 .driver = { 431 .name = "display-connector", 432 .of_match_table = display_connector_match, 433 }, 434 }; 435 module_platform_driver(display_connector_driver); 436 437 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>"); 438 MODULE_DESCRIPTION("Display connector driver"); 439 MODULE_LICENSE("GPL"); 440